The economics of broadcast television have practically demanded that this happen, because networks make money in a brutally elemental way: Multiply the number of viewers by the price charged to advertisers to reach them, and multiply that by the number of commercials sold per day. Broadcasters sell out almost 100% of their inventory, so the amount that a network earns is a function of ad pricing, ratings and production expenses.
Network execs used to live and die on their ability to deliver a large number of viewers. Now they have the added, urgent task of ensuring viewers also won't skip advertisers' messages. The problem in recent years is that ratings and ad prices have both fallen. Even in the second quarter of this year, ratings sank 6% among adults 18 to 49 in every time period, from prime time to weekends. The largest part of the dip came from a 9% slide in male viewers. Female viewers were down 4% at all networks except Fox, the television arm of News Corp.


